Abstract:

Study on the non spatial structural characteristic and its dynamic change in moso bamboo (Phyllostachys edulis) forests would have important theoretical and practical significance for sustainably managing bamboo forest, understanding bamboo forest carbon sequestration capacity and improving forest productivity. In the present study, seven parameters, including biomass, number of trees, average diameter at breast height (DBH) of culms, proportions of 1 du, 2 du, 3 du, and ≥4 du moso bamboos, were used to describe the non spatial structural characteristic of moso bamboo forests. Factor analysis, cluster analysis, correlation analysis, multivariate analysis of variance, and kernel density estimation were conducted with the data collected from two consecutive inventories in bamboo plots. Results showed that: Age structure, plot biomass, average diameter of stands were the dominant factors of non spatial structural characteristic in moso bamboo forests.The aging of moso bamboo forests was a severe problem in Zhejiang Province. The proportions of different-age forests were unreasonable and there was drawback in the present management practices, which caused the recession of stand productivity. There was no relationship between average DBH of forests and number of culms when the number of culms in a plot was small, while a negative exponential relationship was observed between the above-mentioned two parameters with the increasing of number of culms.The number of culms and average stand DBH were the two main factors affecting biomass of moso bamboo forests. There were significant differences in the all parameters related to the non spatial structural characteristic except for the proportion of 3 du moso bamboo between the two inventories, thus there was a significant difference in non spatial structural characteristic of forests described with the two inventory data.The proportion of stands with average diameter of less than 8.7 cm was found to be decreased with the growth of moso bamboo, while the proportion of stands with average diameter of more than 8.7 cm increased, indicating that the average diameter of moso bambo forests in 2009 was significant greater than that in 2004. There were similar trends in number of culms in the plot and biomass of forests. The results would provide a certain reference value for the sustainable management of moso bamboo forests and improvement of carbon sequestration.

Key words: Phyllostachys edulis, non spatial structure of forests, multivariate statistical analysis, significant difference